Nearfield acoustic holography(NAH)is a powerful tool for realizing source identification and sound field reconstruction.The wave superposition(WS)-based NAH is appropriate for the spatially extended sources and does n...Nearfield acoustic holography(NAH)is a powerful tool for realizing source identification and sound field reconstruction.The wave superposition(WS)-based NAH is appropriate for the spatially extended sources and does not require the complex numerical integrals.Equivalent source method(ESM),as a classical WS approach,is widely used due to its simplicity and efficiency.In the ESM,a virtual source surface is introduced,on which the virtual point sources are taken as the assumed sources,and an optimal retreat distance needs to be considered.A newly proposed WS-based approach,the element radiation superposition method(ERSM),uses piston surface source as the assumed source with no need to choose a virtual source surface.To satisfy the application conditions of piston pressure formula,the sizes of pistons are assumed to be as small as possible,which results in a large number of pistons and sampling points.In this paper,transfer matrix modes(TMMs),which are composed of the singular vectors of the vibro-acoustic transfer matrix,are used as the sparse basis of piston normal velocities.Then,the compressive ERSM based on TMMs is proposed.Compared with the conventional ERSM,the proposed method maintains a good pressure reconstruction when the number of sampling points and pistons are both reduced.Besides,the proposed method is compared with the compressive ESM in a mathematical sense.Both simulations and experiments for a rectangular plate demonstrate the advantage of the proposed method over the existing methods.展开更多
Under the background of aging population, facing the silver wave of strikes, the whole society should prepare the attendant opportunities and chaUenges. The aging society is a big trend, and the phenomenon that can no...Under the background of aging population, facing the silver wave of strikes, the whole society should prepare the attendant opportunities and chaUenges. The aging society is a big trend, and the phenomenon that can not be ignored will affect the life of each of us. Coincides with the party and the government advocates the policy background of the harmonious society, how to provide services effectively for the older age groups, not only related to the well-being of older age groups and will in the social relations of each individual has a personal positive externalities. So pay attention to the aging is a urgent measures, begin to solve problems caused by aging and meet with aging opportunities, only to rely on binary structure composed of government and business is slightly lack of power, we must to play a wide range of social forces involved. Social forces through the third deparunents in the form of organization, this paper focuses on the third sector to participate in the study of the old service.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61701133)。
文摘Nearfield acoustic holography(NAH)is a powerful tool for realizing source identification and sound field reconstruction.The wave superposition(WS)-based NAH is appropriate for the spatially extended sources and does not require the complex numerical integrals.Equivalent source method(ESM),as a classical WS approach,is widely used due to its simplicity and efficiency.In the ESM,a virtual source surface is introduced,on which the virtual point sources are taken as the assumed sources,and an optimal retreat distance needs to be considered.A newly proposed WS-based approach,the element radiation superposition method(ERSM),uses piston surface source as the assumed source with no need to choose a virtual source surface.To satisfy the application conditions of piston pressure formula,the sizes of pistons are assumed to be as small as possible,which results in a large number of pistons and sampling points.In this paper,transfer matrix modes(TMMs),which are composed of the singular vectors of the vibro-acoustic transfer matrix,are used as the sparse basis of piston normal velocities.Then,the compressive ERSM based on TMMs is proposed.Compared with the conventional ERSM,the proposed method maintains a good pressure reconstruction when the number of sampling points and pistons are both reduced.Besides,the proposed method is compared with the compressive ESM in a mathematical sense.Both simulations and experiments for a rectangular plate demonstrate the advantage of the proposed method over the existing methods.
文摘Under the background of aging population, facing the silver wave of strikes, the whole society should prepare the attendant opportunities and chaUenges. The aging society is a big trend, and the phenomenon that can not be ignored will affect the life of each of us. Coincides with the party and the government advocates the policy background of the harmonious society, how to provide services effectively for the older age groups, not only related to the well-being of older age groups and will in the social relations of each individual has a personal positive externalities. So pay attention to the aging is a urgent measures, begin to solve problems caused by aging and meet with aging opportunities, only to rely on binary structure composed of government and business is slightly lack of power, we must to play a wide range of social forces involved. Social forces through the third deparunents in the form of organization, this paper focuses on the third sector to participate in the study of the old service.
